That's in addition to the 70 mining claims the company filed last year with the U.S. Bureau of Land Management on the adjacent Rose Canyon Ranch in the southern Oquirrh Mountains.

County officials think Kennecott might be getting a little greedy.

"Personally I think they have plenty of land at this point to explore and should allow the citizens to maintain some of it for their own use," Mayor Peter Corroon said.

Kennecott has every right to file a mining claim.

The 80 acres in Yellow Fork Canyon are subject to the Stock Raising Homestead Act, a piece of legislation passed in 1916 that allows people to file mineral-rights claims on land that has little value other than for livestock grazing and ranching.

The county owns 800 acres in Yellow Fork Canyon, but only 80 acres are subject to the Stock Raising Homestead Act.

If Kennecott happens to find some hard minerals underneath the county's open-space land, the BLM would then determine whether Kennecott could actually start mining. Technically the minerals are federally owned.

For now, though, Kennecott does have the right to start some casual-use testing, said Lorna Vogt, the county's open-space manager. After a 30-day grace period, Kennecott will start taking soil samples and using induced polarization, a geophysical imaging technique used to identify subsurface materials such as ore.

The company cannot, however, start drilling of any sort until the BLM approves a mining plan. If and when that happens, Corroon said he'll fight it.

Kennecott officials reached late Thursday night said they could not elaborate on the plan.

The company is also eyeing the huge, county-owned Rose Canyon Ranch as a potential hot spot for minerals.

Last fall, Kennecott filed documents with the BLM looking for mineral claims in Rose Canyon Ranch, nearly 1,700 acres of untouched mountain land in the south valley. County officials purchased the land last fall for $8.7 million.

That land, combined with Yellow Fork Canyon and some adjacent BLM land, represents the county's largest piece of untouched land, at about 4,000 acres.

Corroon wants to make sure it stays that way.

"This land is intended to be for the citizens' use and enjoyment," Corroon said. "We'd like to see it remain that way."